Clad metal.



UNITED STATES PATENT OFFICE.

JOHN F. MONNOT, OF NEW YORK, N. Y., ASSIGNOR TO DUPLEX METALS COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

GLAD METAL.

Patented July 6, 1909.

To all whom it ma/y concern:

Be it known that 1, JOHN FERaEoL MON- NOT, a citizen of the 'United States, residing at New York, in the county and State of New York, have invented certain new and valuable Improvements. in Clad Metals; and I do hereby declare the followin to be a full, clear, and exact description 0 the same, such as will enable others skilled in the art to,

which it appertains to make and use the same.

This invention relates to clad metals; and comprises compound metal articles comprisinga base of ferrous metal carrying a weldedon layer of a ferrous alloy of copper or like metal of high melting point permanently and indissolubly united thereto; all as more fully hereinafter set forth and as claimed.

In the prior art, many unsuccessful attempts have been made to provide the strong, stifi, cheap ,and malleable ferrous metals with surface coatings of copper, cop per alloys and copperlike metals, such as silyer and gold, by casting such coating metals in a molten state against the surface of the ferrous metal, or by casting the ferrous metal in a molten state against the non-ferrous metal, but by reason of the pronounced lack of affinity existing between iron and the ironlike metals onthe one hand and copper and the copper-like metals on the. other hand at the temperatures at which copper and like metals become liquid or-plastic, andalso because of failure to prevent oxidation of one or both of the metalspr to remove oxid formed, these attempts have failed to produce any permanent union, or the product has been so porous, filled with blowholes, and of uneven quality, as to be unmarketable. In coating ferrous metals, resort has generally, therefore, been had to electrolytic coating processes, but as electro-depos'lted metal 18 Invariably porous, having intercrystalline spaces permittin access of corrosive 'va ors, gases and liqui s to the underlying oxi izable ferrous metal, and has no more than a simple adhesion, as distin uished from a cohesion,

to the base metal, e ectrocoated metals have.

not been found suitable for uses or situations where corrosion was likely. I have however discovered thatthis lack of affinity between iron and the iron-like metals, such as cobalt, nickel, etc. 'on the one hand and co per and thecopper-like. metals, such as s' ver and gold (and for the present purposes, aluminum may be here classed) and their alloys,

which subsists at the common casting 'tem- I peratures of co per, etc., and at the lower temperatures w ere copper is soft and plastic, disap ears when these copper-like metals are raised to a tem erature much above their melting oints, allowing the production of good an permanent unions of a weldlike nature. At this elevated temperature, co per :and like metals assume a eculia'r con ition which I have termed, for ack of another name, the supermolten condition in which they dis lay much enhanced aflinities, both chemica and physical.

Copper heated much above its melting point and contacted with'a clean steel surface readily unites therewith to form a union which is in the nature of, if it be not actually, a weld-union. A layer of copper and a layer of steel so joined cannot be again separated by the action of cleaving tools, such as a cold chisel, the tool, refusing to follow the line of union and veering off into thesofter metal; nor can they be parted by even such a severe test as heating the joined metals to redness and quenching, or by destructive torsion. As to the nature of the union which subsists I cannot say, save that it appears to be in the nature of a weld-union such as can be produced between iron-and iron or gold and gold. It'may be that a tenuous layer of an alloy of the two metals occurs along the line of union; or it may be indefinite coextension of the joined metals, with such ductile and malleable metals as copper and steel, in a direction parallel to the as by drawing, rolling, spinning, stam ing, etc., with substantial preservation of t e initial ratio between the thicknesses of the la ers of such metals. A three or four inch b" et carrying a coating of, say 10 to 20 per cent. copper so joined ma be rolled and drawn down to wire of hair ike thinness, or, say, totwo or three thousandths of an inch in diameter without the copper coating per} ishing or exfoliating, and with substantial preservance of the initial ratio between co vper and steel throughoutthe extension.

such extension, the relatively thin copper layer being compressed between the steel base to which it 1s welded (and by which it is held against lateral movement) and the extending tool, assumes a peculiar condition of density and hardness throughout, comparable with the superficial condition of harddrawn co per wire. The copper, having been attac ed in a liquid condition, shares in the property of li uids and set liquids of being poreless and hense; and, as stated, in coextension with the steel, it is still further compacted and hardened.

In a prior patent, No. 853,716, May 14, 1907, I have described and claimed a process of uniting iron and iron-like metals founded upon the properties of supermolten metals; and in application Serial No. 358,006, filed Feb. 18, 1907, and co-pending herewith, I have claimed copper-clad ferrous metal produced according to said process and having the described properties. In another coending application, Sr. No. 367,985, filed April 13, 1907, I have described and claimed a processof producing silver clad steel and the product thereof, while in copendin application Serial No. 367,987, filed Apri 13, 1907, I have described and claimed old-clad steel and the process of producing t e same.

Similar products comprising ferrous and non-ferrous metals weld-united may be made' by casting the ferrous metal, in a molten state, against the surface of the non-ferrous metal to be united thereto, according to the processes of my applications Sr. Nos. 343,033 and 438,396, in which processes adequate provision ismade forreventing oxidation of the metals or either 0 them, or for removing any oxid which may form, or by the process of my application Sr. No. 358,007, wherein the ferrous metal highly heated, is immersed in the non-ferrous metal under conditions insuring an unoxidized surface, or by a process of W. M. Page, involving the action of heated vapors of metal like zinc or tin on the "ferrous metal surface and the casting of molten copper-like coating surface so treated.

For many purposes, it is desirable to produce steel and ferrous metals clad with various alloys of low-melting metals, such as higher, they are the steel base with a high-melting ductile metal, such as copper or silver, with which such alloys will readily unite or else fihncoating said base by said Page process, and then casting the alloy against such filmed surface at a more convenient castin temperature. By this expedient, brass w ich is often two-thirds zinc, may be readily and easily united to steel though the boiling point of is relatively low.

metal against the In another and copending application, Se

. rial No. 368,770, filed April 17, 1907, I have claimed the described process and products thereof.

Though the ordinary brasses, that is, copper-zinc alloys, and bronzes (copper-tin or copper-tin-zinc alloys) may be so attached to ferrous metals and the produced clad metals used for many purposes, for certain other purposes they suffer from certain disadvantages and are lacking in certain advantages.

Not all the brasses and bronzes will coextend, as by drawing or rolling, with steel at steelworking temperatures as indefinitely as will copper, silver or gold, many such alloys tending to crack or crumble after the extension has reached a certain stage. For articles which are to carry but thin or film-like coatings of simple brass or bronze, it is therefore frequently advisable to produce a preliminary coating of copper on the steel, carry the extension of the clad metal to, ornearly to,

the stage desired and then produce the alloy in place, as more particularly described and claimed in my co-pending application Serial No. 438,680, filed June 15., 1908. There are however certain copper alloys of the nature of brass and bronze but distinguished therefrom by containing iron and other alloying metals which are more tenacious and possess better extending properties than ordinary brass or bronze; working well withsteel at steel working temperatures and being capable of great coextension therewith when joined thereto in the stated manner. A small amount of iron in these alloys produces a great change in their properties in this regard. These alloys, which are generally called alloys of the delta metal or sterro metal types, are, furthermore, highly desirable for a number of special purploses such as marine work since they unite h tensile strength, and in many cases, onsi erable hardness with good resistance against corrosion. Tobin bronze, for example, though containing but a tenth per cent. or so of iron, has a tensile strength of about 79,000 pounds while about as resistive to the action of sea-water as copper. A typical Tobin bronze will have about 59 per cent. copper, 38.40 per cent. zinc, 2.16 per cent. tin, 0.3] lead and 0.11 per cent. iron. A. delta metal will carry about 60 per cent. copper or less, 34 to 44 per cent. zinc, 2 to 4 per cent. iron and 1 to 2 per cent. of tin. These ferrous copper alloys however for any special use must be of quite exact composition, such composition varying with the special use, and they cannot thereforebe exposed to unduly high temperatures or kept heated for a long time, since the more oxidizable metals tend to burn out and change the composition. They must therefore commonly be made directly before use from exact quanti-' ties of the several ingredients. Slight variations in the amount of iron change the character of these ferrous copper alloys materially. And for many purposes it is desirable to have such alloys reinforced by backings of the still stronger and stiffer ferrous metals-and the more so since such ferrous metals are commonly cheaperprovided the ferrous backing can be completely shielded and isolated bysuch alloy. In a ship plate, for instance, it is desirable to have the smooth, sli htly frictional, non-corroding surface of obin bronze but it is not necessary, if a strong metal backing can be provided, that the thickness of the bronze layer be very great. On the other hand, it is desirable to have the strength and stiffness of 1 invention, such bodies of steel if such steel can be thoroughly protected from corroding influences. In the present- V duplex or compound metal are provided. To this end, a steel or iron billet, ingot or other body is preliminarily produced. carrying a welded-on coating of copper, silver, aluminum bronze or other metal capable of withstanding the very high supermolten temperatures. This coating may be produced according to the clean surface on the steel body process described in my Patent 853,716, which, briefly stated, comprises producing a and momentarily contacting it, as by. dip ing, with .a mass of copper maintained in t e ,supermol-- ten condition. Upon Withdrawal, the dipped billet will be found covered with a thin, cohering coatin of cop er having the described properties. heb1llgt before and after dipping must be preserved against oxidation by suitable air-excluding means, as by the use ofcasings filled with producergas or the use of protective coatings of flux. Against one or all surfaces of this filmed billet may now be cast the desired amount of theferrous' copper alloy. While such alloy at the common casting temperature will not cohere directly with and to steeL-and moreover when contacted with steel in a molten condition is likely to take up, more than the exact amount of iron desired in its composition, it will-cohere readily to the copper of the filmed surface and cannot, of course, take up iron therefrom. After casting the alloy against such filmed surface, the compound metal article ma be allowed to cool and may then be reheated and worked, or it may be directly worked while still retaining the heat due to the operation. The alloy may be, and preferably is, made directly before the operation by melting the co per, adding thereto the de-' slred amount of t e other ingredients and applying while still molten.

In a clad metal body according to thepresent invention, the steel core or base may be of any of the usual grades or varieties of steel or iron, or any of the various alloy steels, such as nickel steel, cobalt steel, manganese steel, chrome steel, vanadium steel, etc.,

etc.; the linking metal may be copper or a high melting alloy thereof; and the coatin may be an of the binary or ternary alloys 0 copper an iron, such as sterro or delta metal, Tobin bronze, manganese bronze, etc., or ferrous alloys of silver, gold, aluminum etc. The linking metal and the alloy having been attached as liquids possess the poreless characteristics of liquids and set li uids, and the coating of the steel is there ore po'reless,

dense and impervious to corrosive agencies, the steel being thoroughly shielded against corrosion thereby. In the coextension of the joined metals, the coating is still further compacted and hardened, as described.

For many purposes, the original billet, bar or plate of steel or other ferrous metal ma be filmed with the linking metal, the ful amount of the alloy coating cast against the filmed surface and the compound bod produced then directly worked down to t we finished form by drawing, rolling, spinning, or

hammering. Or, if desired, the original large billet, etc., may be film-coated and worked to smaller dimensions prior to attaching the alloy-coating, such coating attached and the compound body then reduced to the final dimensions. V

In the clad metal body produced, before or after working, the line of union between the joined metals cannot be discovered by cleavlng tools, such as a cold chisel, nor can such metals be parted by heating and quenching or by torsion to rupture.

Some of the alloys of copper, silver, gold, aluminum, etc., with iron, containing small amounts of iron, particularly the binary 'alloys, may be directly attached to steel by heating to a supermolten temperature, since they'will withstand such a temperature, provided the contacting be but momentary since otherwlse more iron will dissolve, disturbin 'the exactitude of their composition, but or alloys through the intermediacy of a linking coat of copper previously welded to the iron, thereby precluding the possibility of solution of more iron in such alloy. Such al- 10 s, also, are best made ust rior to the y i P coating operation by disso ving the correct,

amount of iron (best nearly carbon-free) in inarily it is better to attach even such the molten copper 'or copperlike metal. In-

stead of producing such unions by the suermolten method, they may be produced l; the methods of my said applications Sr, os. 343,033, 438,396 and 358,007. A method of producing weld-unions set forth in an application for Letters Patent Serial No. 443,298, filed July 13, 1908, comprising the casting of the metals to be united on opposite sides of a metallic separator under conditions precluding oxidation or with provision of means for removlng oxld whlch ma have formed, as for example, by use of mo ten wiping material and so causing both of ferrous metal carrying a welded-on, dense,

impervious, continuous layer of an alloy comprising iron and copper or copper-like metal; said metal base and said layer being united by a firm, permanent cohermg union resisting cleaving tools, temperature chan es and mechanical stresses; and said alloy eing of re ulated composition. v

2, A 0 ad metal article comprising a base of ferrous metal carrying a welded-on, dense,

impervious, continuous layer of an alloy comprising copper and iron and united there to through the intermediacy of a high-melting, ductile non-ferrous metal welded to the metals on either side; said metal base and said layer being united by a firm, permanent, cohering union resisting cleaving tools, temperature changes and mechanical stresses.

3. A clad metal article comprising. a base of ferrous metal carrying a welded-ondense, impervious, continuous layer for an alloy comprising copper and iron through the intermediacy of copper welded to the metals on either side; said metal base and said layer being united by a firm, permanent, coherlng union resisting cleaving tools, temperature changes and mechanical stresses.

4. A clad metal'article comprising a base of ferrous m'etal carrying a welded-on, dense,

impervious, continuous layer of a ternary alloy comprising copper, iron and another and lowmelting metal through the intermediacy of a high-melting ductile non-ferrous metal welded to the metalson either side; said metal base and said layer being united by a firm, permanent, cohering union resisting cleaving tools, temperature changes and mechanical stresses.

5. A clad metal article comprising a base of ferrous metal carrying a welded-on, dense, impervious, continuous layer of a terliary al by comprising copper, iron and another and low-melting metal through the intermediacy of copper Welded to the metals on either side; said metal base and said layer being united by a firm, permanent,.coher-ing union resisting cleaving tools, temperature changes and mechanical stresses.

In testimony whereof, I afiix my signature in the presence of two subscribing wltnesses.

. JOHN F. MONNOT Witnesses H. M. MARBLE, FRANK E. RAFFMAN. 

